One answer is just 3 people switch. Ezra Klein provides interesting take here. Only 13 Dems voted for a procedural motion late in the game that would have killed the bill. Most of the others want a bill, just not this one. Key sticking areas for more conservative Dems, which are probably alot like many Dems in the Senate:
*income tax increase for those making $500k or $1Million for couples >>>>in the Senate finance committee there is a tax on high cost health insurance
*Public option >>>>Reid talking about public option, but this must surely be wabbling now....must hold Lieberman to even get debate started and says he will join filibuster at the end if any public option in. And the public option is weak in any event, certainly not worth killing the entire thing.
*employer mandate in House bill >>>>>>>>>there is not one in Senate
interesingly, the abortion restriction is fairly stringent, banning not only use of public money, but from any insurance sold via exchange including abortion even if paid for with individuals own money. This seems to be price to get enough Blue Dogs to vote yes and kick the ball down the field....but that may be too conservative in the Senate.
I think adding more on med malpractice in the Senate and then seeing if you can get started with public option in and dropping it if you can't. They already have the weak public option in the conference discussion, but it seems like it will have to go out. I guess you would rather fold on it at conference so it seems a big concession.....but it is not worth killing the bill over.